How fertilization and thinning may impact tree defense and mountain pine beetle overwintering
Devin Goodsman, Vic Lieffers, Nadir Erbilgin, and Simon Landhausser Centre for Enhanced Forest Management Department of Renewable Resources University of Alberta www.shim.bc.ca/atlases/fbc/ss3/Forest.html
Overview:
1. Fertilization and thinning and tree carbohydrate reserves 2. Mountain pine beetle overwinter survival in bolts from fertilized lodgepole pines
www.forrex.org
Carbohydrates in trees Sugars: mobile
Starches: Immobile, reserves
Objectives: How does growth, stem size impact carbohydrate reserves? Growth Photosynthesis
Carbohydrate Supply Defense
Growth Photosynthesis
Carbohydrate Supply Defense
Experimental Design
1800
16
B
A
AB
1200 A
600
0
Root Starches (% Dry wt)
Growth Increment Area (mm²)
Fertilization Increased Growth Increment but decreased starch reserves A
AB 12 AB B 8
4
0
C
F
FT
T
C
F
FT
T
Root starch (% dry wt)
Length of branchless stem impacts carbohydrate reserves in the roots
Study 2: What if beetles kill and colonize fertilized lodgepole pines?
630ched.com
Description of experiment
Description of experiment
Description of experiment
More beetles survived in fertilized bolts
No impact of N on fungal growth (G. clavigera, L. longiclavatum, O. montium)
Fungi amplify nitrogen more effectively in fertilized bolts
Study 2: Implications 1. Fertilization increases phloem Nitrogen 2. Further amplified by fungal associates 3. increased survival and development rates in our beetles
Overall management implications 1. Fertilization reduces carbohydrate reserves in pine trees (For Ecol Manage (260): 1914-1920) 2. In fertilized trees, brood productivity will be higher (Upcoming issue of Environmental Entomology)
Thank you University of Alberta: Candace Serben Caroline Lecourtois Christine Dahl Eckehart Marenholtz Evan Esch Kim Stang Lucas Veldhoen Ryan Sherrit Pak Chow
Alberta SRD: Adrianne Rice Anina Hundsdoerfer Barry White Brooks Horne Darryl Gilday Dave Morgan Devin Letourneau Jeffrey Mallete
FGYA